A novel orange-red emitting K5Y(MoO4)4:Sm3+ phosphor with excellent color purity for temperature sensing and high CRI WLEDs

The novel orange-red emitting K 5 Y(MoO 4 ) 4 : x Sm 3+ (KYMO: x Sm 3+ ) (1 mol% ≤  x ≤ 35 mol%) phosphors were synthesized through solid-phase reaction. The KYMO:Sm 3+ phosphors were mainly analyzed for purity phase, luminescence properties, and thermostability. Under 403 nm excitation, KYMO:10 mol%Sm 3+ possesses four distinct emission peaks. The dominant emission peak is situated at 645 nm, corresponding to the 4 G 5/2  →  6 H 7/2 electron transitions. With x  = 10 mol%, the KYMO: x Sm 3+ phosphor has the optimal doping concentration. The color purity reaches as high as 99.9 %. KYMO:10 mol%Sm 3+ presents good thermostability with T 0.5 > 480 K and resistance to color drift (Δ E  = 0.012 at 420 K). The lifetime for KYMO:10 mol%Sm 3+ is 1.16 ms. The internal quantum efficiency (IQE) reaches 62.74 %. At 480 K, the maximum temperature sensing sensitivities of the FIR of I 564 /I 599 are 5.19 × 10 −4 ( S a ) and 18 % ( S r ). The assembled WLED displays an excellent color rendering index (CRI, R a ) of 94, Commission International de L′ Eclairage (CIE) coordinates (0.333, 0.346), and a correlated color temperature (CCT) of 5464 K. In summary, KYMO:Sm 3+ phosphors possess great promise for high CRI white-light-emitting diodes (WLEDs) and potential feasibility for temperature sensing.